• Explosives and Blasting
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• v.34 no.3
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• pp.1-9
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• 2016

The shaped charge were made for identifying the effect of controled blasting using relatively low VOD explosive for cutting rock mass with changing quality and thickness of metal liner. The metal liner was attached on both sides of a charge for directional cutting, when the shaped charge exploded in rock mass. Also, a efficiency of shaped charge was identified by concrete member experiment. And a center guide used for maintaining stand-off between shaped charge and hole wall. A case of Fe liner of thickness 0.8mm formed the deepest notch of experiments and the directional cutting of concrete member was identified.

• Journal of Korea Ship Safrty Technology Authority
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• s.32
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• pp.2-11
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• 2012

강화플라스틱(FRP)이 가진 저비용 장점에 비하여 화재 및 환경오염 문제가 대두됨에 따라서 알루미늄 소형 선박에 대한 수요가 증가하고 있다. 알루미늄 재질의 선박 건조에도 절단, 성형, 용접 및 조립의 과정이 필요하지만, 소형 선박에는 박판이 사용되기 때문에 일반 강선과는 다른 공법 및 가공 조립법이 사용된다. 본 기사는 알루미늄 재료의 절단 공법, 용접 공법의 현황과 미래 기술 방향을 정리하였다. 또한 성형 공정의 문제점과 이를 위한 개선 방안을 제시함으로써 알루미늄 선박의 건조 생산성 향상 및 정도 관리의 편의성을 위한 방안을 모색하고자 한다.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.12
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• pp.150-158
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• 2013

In this paper we present approximated constrained least squares filter for real-time directionally adaptive image restoration. The proposed method makes a hardware implementation easier for real-time image restoration because of reducing the filter size. Furthermore, for directional adaptive image restoration, this paper estimates the local orientation by analyzing the covariance matrix and applies to approximated constrained least squares filter. Experimental results show that the proposed method is sharper and less artifacts than existing methods.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.1
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• pp.120-130
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• 1994

The leadwire cutting machine that has been used recently cuts leadwires by putting one-side force with the same priciple as a saw, and applies a stress at soldered part of PCB. Because the stress becomes one cause of contact-defect, a leadwire cutting robot that cuts leadwire-site with nipper and does not apply stress is considered, In this paper a technique of detecting leadwire-site is studied for the purpose of using on automatic leadwire cutting robots. A technique deriving 2-dimensional site-information with many I-dimensional binary data of perspective front-view of PCB taken from various direction was proposed. Simulation and experiments were done under the same condition each other and a small universal PCB was choosen as an experimental object. As a result of simulations and experiments, the proposed technique turns out to be very useful for automatic leadwire cutting robots.

• Explosives and Blasting
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• v.37 no.4
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• pp.17-25
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• 2019

The method to remove the head of the cast-in-place pile using the detonating cord and horizontal separation plate was proposed in this paper. Plain concrete block was fabricated. Through the blasting test of the concrete block, the charge weight and the burden required for cutting the pile head were identified. The degree of damage of concrete blocks after cutting the head was checked using AUTODYN 2D. As a result of the experiment, it was found that the concrete block was cut using the 10 g/m detonating cord and horizontal separation plate, and the directional cutting of the block using the horizontal separation plate and the block damage caused by the detonating cord were reduced.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.10 no.4
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• pp.305-313
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• 2016

Movements of the lower limb are important for normal walking and smooth oscillation of the center of gravity. The ankle rotations such as dorsi-flexion, plantar-flexion, inversion and eversion allows the foot to accommodate to ground during level ground walking. Current below knee (B/K) prostheses are used for replacing amputated ankle, and make it possible for amputees to walk again. However, most of amputees with B/K prostheses often experience a loss of terrain adaptability as well as stability because of limited ankle rotation. This study is focused on the development of multi-rotational prosthetic foot for lower limb amputee. Our prosthesis is possible for amputees to easily walk in level ground by rotating ankle joint in sagittal plane and adapt to the abnormal terrain with ankle rotation in coronal plane. The resistance of ankle joint in the direction of dorsi/plantar-flexion can be manually regulated by hydraulic damper with controllable nozzle. Furthermore, double layered rubber induce the prosthesis adapt to irregular ground by tilting itself in direction of eversion and inversion. The experimental results highlights the potential that our prosthesis induce a normal gait for below knee amputee.

• Proceedings of the KGS Conference
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• 2005.05a
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• pp.195-196
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• 2005

본 연구는 산경표에 기초한 최근 한국 산맥논의를 검토하였다. 산경표는 풍수지리학에 기초를 둔 우리나라 전통 산맥 체계로 분수계 체계이다. 이 체계에 기초를 둔 논의들은 하천이 산맥을 절단하고 있는 것을 받아드리지 못하며, 이 체계의 중심 맥인 백두대간은 많은 기원이 다른 산맥들을 연결하여 이름하고 있다. 지형학에서 산맥은 구조 운동이나 차별 침식의 결과로 형성된 산지의 선적 배열이다. 같은 원인에 의하여 형성된 산지의 선적 배열을 하나의 산맥으로 이름을 부여하고, 형성 원인이 다르거나 방향성이 다른 것을 합쳐서 하나의 산맥으로 이름 하지 않는다. 지형학에서 정의되는 산맥은 선행 하천에 의해 절단될 수 있고, 분수계 이동 현상도 일어나기 때문에 산맥이 분수계와 일치하는 것은 아니다. 따라서 백두대간이란 이름은 우리나라의 상징성을 표현할 때 사용하고, 교과서에서는 우리나라의 지형을 설명할 때는 기존의 산맥체계를 사용해야 할 것으로 본다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.72-77
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• 2017

This paper focuses on the development of a supporting S/W tool for the automated design of an automotive press trim die. To define the die design process based on automation, we analyze the press die design process of the current industry and group repetitive works in the 3D modeling process. The proposed system consists of two modules, namely the template models of the trim steel parts and UI function for their auto-positioning. Four kinds of template models are developed to adapt to various situations and the rules of the interaction formula which are used for checking and correcting the directions of the datum point, datum curve, datum plane are implemented to eliminate errors. The system was developed using CATIA Knowledgeware, CAA(CATIA SDK) and Visual C++, in order for it to function as a plug-in module of CATIA V5, which is one of the major 3D CAD systems in the manufacturing industry. The developed system was tested by applying it to various panels of current automobiles and the results showed that it reduces the time-cost by 74% compared to the traditional method.

• Journal of the Microelectronics and Packaging Society
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• v.18 no.3
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• pp.25-32
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• 2011

We have studied on the slicing and polishing processes of R-plane sapphire wafers for the substrates of UHB nonpolar a-plane GaN LED. The fabrication conditions of the R-plane and c-plane wafers were influenced by the large anisotropic properties (mechanical properties) of the sapphire. The slicing process was more affected by the anisotropic properties of R-plane than the polishing process. When the slicing direction was $45^{\circ}$ to the a-flat, the slicing time was shorter and the quality of as-slicing wafers was better than the slicing direction of normal to the a-flat. The MRR(Material removal rate) of mechanical polishing processes such as lapping and DMP(Diamond mechanical polishing) did not show significant differences between the R-plane and c-plane. The MRR of the c-plane was about two times higher than that of R-planes at the CMP(Chemical mechanical polishing) process due to the formation of hydrolysis reaction layers on the surface of the c-plane.

• The Korean Journal of Applied Statistics
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• v.32 no.4
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• pp.593-605
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• 2019

Significant literature exists on the area under the ROC curve (AUC) and the volume under the ROC surface (VUS) which are statistical measures of the discriminant power of classification models. Whereas the partial AUC is restricted on the false positive rate, the two-way partial AUC is restricted on both the false positive rate and true positive rate, which could be more efficient and accurate than partial AUC. The two-way partial AUC was suggested as more efficient and accurate than the partial AUC. Partial VUS as well as the three-way partial VUS were also developed for the ROC surface. A proposed AUC is expressed in this paper with probability and integration using two truncated distribution functions restricted on both the false positive rate and true positive rate. It is also found that this AUC has a relation with the two-way partial AUC. The three-way partial VUS for the ROC surface is also related to the VUS using truncated distribution functions. These AUC and VUS are represented and estimated in terms of Mann-Whitney statistics. Their parametric and non-parametric estimation methods are explored based on normal distributions and random samples.